p53 ubiquitination co-mediated by HUWE1 and TRAF6 contributes to WSSV infection in crustacean

Large-scale lysine crotonylation analysis reveals the role of TRAF6-Ecsit complex in endoplasmic reticulum stress in mud crab (Scylla paramamosain)

Lysine crotonylation (Kcr) is a newly discovered type of post-translational modification. Although Kcr has been reported in several species, its role in crustaceans remains largely unknown. In this study, Kcr in hemocytes of mud crab (Scylla paramamosain) was characterized using pan anti-crotonyllysine antibody enrichment and high-resolution liquid chromatogram-mass spectrometry analysis after SpTRAF6 or SpEcsit silencing. Altogether, 1,800 Kcr sites with six conserved motifs were identified from 512 proteins. Subcellular localization analysis showed that the identified Kcr proteins were mainly localized to the cytoplasm, nucleus, and mitochondria. The cellular components analysis showed that the 'chromosomal region' was enriched in the hemocytes of SpTRAF6-or SpEcsit-silenced mud crabs. The KEGG and PPI analyses showed that the identified Kcr proteins in the hemocytes SpTRAF6-or SpEcsit-silenced mud crabs were related to the 'protein processing in endoplasmic reticulum'; of which the marker of endoplasmic reticulum stress (Bip) was identified to be crotonylated. These datasets present the first comprehensive analysis of the crotonylome in mud crab hemocytes, providing invaluable insights into the regulatory functions of SpTRAF6 and SpEcsit in Kcr. Additionally, our findings shed light on the potential role of these proteins in activating marker proteins during endoplasmic reticulum stress in invertebrates.

Role of Cellular Receptors in the Innate Immune System of Crustaceans in Response to White Spot Syndrome Virus

Innate immunity is the only defense system for resistance against infections in crustaceans. In crustaceans, white spot diseases caused by white spot syndrome virus (WSSV) are a serious viral disease with high accumulative mortality after infection. Attachment and entry into cells have been known to be two initial and important steps in viral infection. However, systematic information about the mechanisms related to WSSV infection in crustaceans is still limited. Previous studies have reported that cellular receptors are important in the innate immune system and are responsible for the recognition of foreign microorganisms and in the stimulation of the immune responses during infections. In this review, we summarize the current understanding of the functions of cellular receptors, including Toll, C-type lectin, scavenger receptor, β-integrin, polymeric immunoglobulin receptor, laminin receptor, globular C1q receptor, lipopolysaccharide-and β-1,3-glucan-binding protein, chitin-binding protein, Ras-associated binding, and Down syndrome cell adhesion molecule in the innate immune defense of crustaceans, especially shrimp and crabs, in response to WSSV infection. The results of this study provide information on the interaction between viruses and hosts during infections, which is important in the development of preventative strategies and antiviral targets in cultured aquatic animals.